Early haemodynamic benefit of sildenafil in patients with coexisting chronic thromboembolic pulmonary hypertension and left ventricular dysfunction

Abstract

Sildenafil, a phosphodiesterase type-5 inhibitor, offers potential to treat pulmonary hypertension associated with a variety of conditions. We assessed the early impact of sildenafil on a cohort of patients referred to our unit who had severe pulmonary hypertension secondary to chronic thromboembolic disease which was not amenable to pulmonary thromboendarterectomy and who also had coexisting left ventricular dysfunction. Six patients were studied. Diagnosis of pulmonary embolic disease was made by ventilation perfusion scanning and/or CT pulmonary angiography. All patients were anticoagulated with oral coumarin derivatives and none were considered suitable for pulmonary thromboendarterectomy. Pulmonary hypertension was diagnosed by right heart catheterisation and each patient had Medical Research Council (MRC) dyspnoea score and New York Heart Association (NYHA) class noted and 2D echocardiography prior to commencement of sildenafil 50 mg three times a day. After 6 weeks of sildenafil therapy, right heart catheterisation and 2D echocardiography were repeated, and MRC dyspnoea score, NYHA class and exercise capacity were recorded. All patients demonstrated an improvement in mean pulmonary artery pressure, mean pulmonary capillary wedge pressure, MRC dyspnoea score, NYHA class and gas transfer. No adverse effects of sildenafil were noted. Our data suggests that sildenafil is an effective and well-tolerated therapy for patients with severe pulmonary hypertension associated with pulmonary thromboembolic disease and impaired left ventricular function, producing beneficial effects as early as 6 weeks.